To Foam or Not to Foam - that is the question

O

OldCorpse

Rockin the Boat
I was wondering if when you put on a blimp, do you leave the foam on the mic or take it off? Apparently opinions differ. First there is John Willet - who I believe posts here - he thinks you should definitely take it off:

"BTW, one more question...Do you leave the foam windscreen on the mic when using a blimp, or remove it?

VERY IMPORTANT

You should always take the foam windshield OFF when the microphone is in the basket.

The foam does *not* give added protection - it actually reduces the protection and makes it worse.

Wind protection is governed by the volume of still air around the microphone - inside a basket windshield the foam windshield reduces the volume of air and thus makes the protection worse if you leave it on.

This was explained to me in detail by the one person who designs wind protection and shockmounts and really understands the science behind it all (which is more than can be said for most of the copy products)."

On the other hand, Fred Ginsburg over at Film Underground believes leaving it on (as long as there is also air space left over) adds extra protection against windnoise:

"For instance, using a thin foam windscreen over the microphone INSIDE of the blimp provides a major increase of wind protection. Make sure to leave plenty of airspace between the foam and the inside of the blimp, or else you will defeat the purpose of multi-stage wind reduction. That layer of non-moving air is vital."

Now of course, Fred also makes the sensible point that you want just enough protection to take care of the problem, but not more, because that can degrade the quality of sound:

"An important guideline to follow when using windscreens is to only use as much barrier protection as is needed, but never less than what is needed. The more stuff you surround your mic with, the more you will interfere with the frequency response and even pattern of your mic."

With that understood, what is the verdict - foam or not foam?
 
Well, it certainly seems to be the case for the AT8035 mic - you simply cannot use the foam on the mic inside the basket. The reason is because the foam that comes with the 8035 covers the entire length of the slotted sides of the mic, and since there is no way to position it in such a way that the pincer cradles don't hold onto the slotted area, the foam would get in the way. Advantage: NO FOAM.
 
I'd agree that physically, it would get in the way. It may also make contact with the basket if the mic is jolted, and surely the entire point of a foam windshield is to prevent wind getting through, despite the foams tendency to remove the top end. If there is little or no air movement inside, the the foam has no wind to remove, but still the top end will go.
 
In Broadcast we tend to leave the foam on but it is for more practical operational reasons as you can then quickly remove the blimp if you have to shoot inside and it stops it getting lost or left in the crew car getting damaged.

We also tend to leave the foam on the mic if it is not in a blimp as far too many 416 mics have been bashed on ceilings and walls! ;0)
 
The foam is going to do nothing but get in the way inside the blimp. The whole idea is to get moving air to go around and let the compression waves (sound) to get through. Since there is no moving air inside the blimp the foam just makes it a tad harder for the compression waves to get through.

Neither, in my experience, make a big difference in the sound. FX recordists pretty much never take the blimp off, indoors or out. The dead cat comes off if not needed though. In production you will probably want some wind protection always because your moving the mic around so you are creating your own "wind" even if there is none in the room.
 
Noiz2 said:
FX recordists pretty much never take the blimp off, indoors or out. The dead cat comes off if not needed though. In production you will probably want some wind protection always because your moving the mic around so you are creating your own "wind" even if there is none in the room.
Click to expand...

The problem with the S-Series though, is that the dead cat is integrated with the blimp basket - you can't take it off. For indoor, is it enough to just use the mic with the foam on if there are no big drafts? If the only air noise comes from swinging the mic around, or people running about, do you need a fuzz pocket on the foam? Also, what is the function of the Baby Ball Gag - plus I see they also have the fuzzy "windjammer" on top of that ball gag... is it for indoor? Seems overkill, no? If for outdoor, how is that better than just a regular blimp?
 
Better? = less weight.

The fake fur will roll off some of the highs. On dialog it really shouldn't be a big deal but as always I would do a test.

The ball gag is not for shotguns so it's not something you are going to use a lot out doors, at least for production.

My limited experience is that foam is usually enough indoors and rarely enough out. If you hardly ever have wind where you are it might work better outside? The fur will make any wind protection more effective. The ball gag is like a mini blimp that only covers the capsule. Since there is less air inside than a normal blimp it is not as effective, but it is a lot lighter so not a bad choice if you don't need the protection of a blimp.

My understanding is that open air protectors are more transparent to sound than the equivalent foam. So given a choice it's a better choice. The trade off is that foam is a lot cheaper, lower maintenance and not enough "less transparent" that many will notice in most cases. It's also easier to pull off and stick on than setting up a blimp.

They all work and the choice often comes down to what you have or what works best for what you do.

As a huge generalization ENG and journalism folks use foam more, and narrative film folks will use blimp like ones more.

Low budget anything will tend toward foam because of cost. Anyone working with a lot of wind will be using something with a LOT of fur.

And as I said above on most voices most of the time for dialog you could leave a blimp and dead cat on all the time and nobody would notice. What you roll off in spectrum has little affect on most voices. So in ENG it's not unusual to see a dead cat indoors, it's faster and safer. But in a big budget feature they are going to go with the least protection they can get away with, they have the time and $$ and they know what's coming next.
 
You must log in or register to reply here.
Back
Top